Originally posted by MSL Has anyone delgassed a TC and then rebuilt it?
Some TCs are very easy to deglass, with no need to disassemble anything; the rings holding the elements simply screw out. In my experience, the ones that aren't easy aren't worth trying. If the ring holding the lens elements has some kind of slot for a lens wrench it is probably the former. If not, probably the latter.
I gather a macro TC has a focusing helicoid? Does the whole thing extend/retract or is the movement internal? In the former case removing the glass would get you an A-type helicoid extension tube, very cool.
I think you're right that these were generally designed for 50mm lenses, at least in that they would get you to 1:1 magnification with a 50.